Pick a final that puts you in a good spot in the powerband for all/most corners so that you aren't bogging in 'gear+1' or redlining in 'gear'. You know how the z33 6MT on SR gets rid of those bog-in-3rd, redline-in-2nd corners. Same deal. I wouldn't worry about picking a final to get the most acceleration since you have more power now but still on the shorter side so you aren't dropping a heap of revs on upshift.
Or get a built LS1, leave it in third and never change gear.